OregonFlora: Astragalus beckwithii vs. Astragalus tyghensis

	Astragalus beckwithii	Astragalus tyghensis
	Weiser's milkvetch	Tygh Valley milkvetch
Habit		Plants perennial, caulescent, canescent villous-tomentose, hairs basifixed.
Stems		several or numerous, prostrate or decumbent to ascending, forming loose mats, 10–55 cm.
Leaves		5–14 cm; leaflets (7)15–21; oval-obovate to elliptic, 6–17 × 2–7 mm; tips obtuse to subacute; surfaces densely villous-tomentose; stipules 3–6 mm; free.
Inflorescences		racemes; dense, closely crowded; ovoid to oblong; later elongating and becoming cylindrical; (10)20–40-flowered; peduncles 5–12 cm; bracts 2–5 mm; pedicels 0.5–1 mm; bracteoles 0.
Flowers		spreading to ascending at anthesis; calyces 6.6–7.8 mm, densely white; silky villous-tomentose; tubes 3.9–4.5 mm; teeth narrowly subulate, 2.7–3.5 mm; corollas 9–12 mm, pale yellow, pubescent, marcescent; ovules 6–8.
Fruits		bilocular, mostly enclosed by persistent calyces, spreading to somewhat declined, obliquely ovoid; straight, obscurely trigonous, 4.5–6 × 3 mm, canescently tomentulose; valves stiffly papery; body contracted basally into stipe-like necks, 0.4–0.6 mm.

	Astragalus beckwithii	Astragalus tyghensis
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion		Dry hillsides and valleys, open pine woodlands, sagebrush communities. Flowering May–Jun. 300–1000 m. Col. Native. Endemic to Oregon. The pubescent petals of this narrow endemic species distinguish it from all other Oregon milkvetches.
Source		Flora of Oregon, volume 2, page 676 Richard Halse
Sibling taxa	A. accidens, A. agrestis, A. alpinus, A. alvordensis, A. applegatei, A. arthuri, A. atratus, A. australis, A. californicus, A. calycosus, A. canadensis, A. caricinus, A. collinus, A. conjunctus, A. curvicarpus, A. cusickii, A. diaphanus, A. drummondii, A. eremiticus, A. filipes, A. gambellianus, A. geyeri, A. hoodianus, A. howellii, A. inflexus, A. iodanthus, A. kentrophyta, A. lemmonii, A. lentiginosus, A. malacus, A. misellus, A. mulfordiae, A. multiflorus, A. newberryi, A. nudisiliquus, A. obscurus, A. peckii, A. platytropis, A. purshii, A. reventus, A. robbinsii, A. salmonis, A. sclerocarpus, A. sheldonii, A. solitarius, A. spaldingii, A. sterilis, A. succumbens, A. tegetarioides, A. tetrapterus, A. toanus, A. tweedyi, A. tyghensis, A. umbraticus, A. vallaris, A. whitneyi	A. accidens, A. agrestis, A. alpinus, A. alvordensis, A. applegatei, A. arthuri, A. atratus, A. australis, A. beckwithii, A. californicus, A. calycosus, A. canadensis, A. caricinus, A. collinus, A. conjunctus, A. curvicarpus, A. cusickii, A. diaphanus, A. drummondii, A. eremiticus, A. filipes, A. gambellianus, A. geyeri, A. hoodianus, A. howellii, A. inflexus, A. iodanthus, A. kentrophyta, A. lemmonii, A. lentiginosus, A. malacus, A. misellus, A. mulfordiae, A. multiflorus, A. newberryi, A. nudisiliquus, A. obscurus, A. peckii, A. platytropis, A. purshii, A. reventus, A. robbinsii, A. salmonis, A. sclerocarpus, A. sheldonii, A. solitarius, A. spaldingii, A. sterilis, A. succumbens, A. tegetarioides, A. tetrapterus, A. toanus, A. tweedyi, A. umbraticus, A. vallaris, A. whitneyi
Subordinate taxa	A. beckwithii var. weiserensis
Synonyms		Astragalus spaldingii var. tyghensis
Web links	Local floras: BC, OR, WA Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: OR Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Astragalus beckwithii

Astragalus tyghensis

Weiser's milkvetch

Tygh Valley milkvetch

Habit

Plants perennial, caulescent, canescent villous-tomentose, hairs basifixed.

Stems

several or numerous, prostrate or decumbent to ascending, forming loose mats, 10–55 cm.

Leaves

5–14 cm;

leaflets (7)15–21; oval-obovate to elliptic, 6–17 × 2–7 mm;

tips obtuse to subacute;

surfaces densely villous-tomentose;

stipules 3–6 mm; free.

Inflorescences

racemes; dense, closely crowded; ovoid to oblong; later elongating and becoming cylindrical; (10)20–40-flowered;

peduncles 5–12 cm;

bracts 2–5 mm;

pedicels 0.5–1 mm;

bracteoles 0.

Flowers

spreading to ascending at anthesis;

calyces 6.6–7.8 mm, densely white; silky villous-tomentose;

tubes 3.9–4.5 mm;

teeth narrowly subulate, 2.7–3.5 mm;

corollas 9–12 mm, pale yellow, pubescent, marcescent;

ovules 6–8.

Fruits

bilocular, mostly enclosed by persistent calyces, spreading to somewhat declined, obliquely ovoid; straight, obscurely trigonous, 4.5–6 × 3 mm, canescently tomentulose;

valves stiffly papery;

body contracted basally into stipe-like necks, 0.4–0.6 mm.